1. Field of the Invention
The present invention relates to a solid catalyst for manufacturing of a nitrile compound and a method of preparation thereof. More particularly, this invention relates to the solid catalyst expressed by the following formula (1), comprising a core catalytic phase expressed by [(100-z)%DdEeFefNigMomOy+z % SiO2] and a shell catalytic phase expressed by [BinAaBbCrOx], which increases a yield in the manufacturing of a nitrile compound via ammoxidation of olelin, and the method of preparation thereof:[BinAaBbCrOx][(100-z)% DdEeFefNigMomOy+z % SiO2]  (1)
wherein A is one or more atoms selected from the group consisting of boron, phosphorus, molybdenum and arsenic;
B is one or more elements having the atomic valence of 1-2 selected the group consisting of potassium, cesium, nickel, cobalt, manganese and magnesium;
C is one or more elements having the atomic valence of 3-6 selected the group consisting of iron, chromium, cerium, niobium, vanadium and tellurium;
D is one or more elements having the atomic valence of 3-6 selected the group consisting of aluminum, cerium and chromium;                E is one or more elements having the atomic valence of 1-2 selected the group consisting of cobalt, manganese, magnesium, calcium, copper and cesium;        
when m is 1, n is 0.001-3, a is 0.001-3, b is 0-3, c is 0-1, d is 0-3, e is 0-3, f is 0.015-5, g is 0.01-5, and z is 0-90; and
x and y are numbers such that the valence requirements of the other elements for oxygen in the core and shell catalytic phase, respectively are satisfied.
2. Description of the Related Art
Acrylonitrile had been prepared via reaction of acetylene or ethylene oxide with HCN before a development of ammoxidation of propylene as raw materials. However, in light of the expensive raw materials employed therein, the problem of economics was apparent, and thus the new method was in need for the improvement thereof.
In addition, in the above process, propylene is oxidized to acrolein and is further oxidized to generate acrylic acid. The process has been recently applied to a manufacture of methacrylic acid and methacrylonitrile via methacrolein by using isobutylene as a reactant.
Acrylonitrile and acrolein have been widely used as a raw material for nitrile-based rubber, plastics, fibers and resin, and prepared by ammoxidation of propylene in the presence of multicomponent oxide catalyst.
About 50 years have passed since the procedure involving ammoxidation of olefin was first invented, and this procedure has been called an “allylic oxidations of lower olefins” up to now since its commercialization 35 years ago.
Now that the economical and industrial significance of such process involving ammoxidation of olefin, which is a catalytic reaction, has been recognized, the research on various aspects of the process have been intensively carried out.
The most noticeable changes have been made in the improvement of chemical compositions of the catalyst and the manufacturing method thereof, including the reaction process. Thanks much to the strenuous research thus far, a better yield of 80% to acrylonitrile in a commercial plant has been obtained, and more than 90% of the yield to acrylic acid in oxidation reaction has been achieved.
It has been reported that the active ingredients of some of the catalysts, which have been used in the commercial plant, are very complicated composite oxides comprising bismuth-molybdenum oxides or iron-antimony oxides as an essential component, together with a variety of additional atoms.
Among the conventional methods, the manufacturing methods of the catalyst, which is similar to the present invention or exhibits remarkable catalytic activity are explained as follows:
The German Patent No. 2,127,996 in 1972 (Ohorodnick, Alexander, etc.) disclosed a novel process of manufacturing acrylonitrile from propylene in the presence of a catalyst derived from Mo—Bi—Fe—P—O series, wherein a Mo—Bi—Fe—P—O catalyst having 58 m2/g of BET specific surface area was impregnated with Fe(NO3)3—9H2O to obtain a catalyst having 7.3 m2/g of specific surface area. The above patent disclosed that such catalyst had the following activity at the temperature of 470-485° C.: conversion was 91.0%, and selectivity was 75.2% to acrylonitrile.
According to the U.S. Pat. No. 4,052,332 in 1977 (du Pont de Nemours, E.I., and Co.) designed to regenerate a Bi—Mo—P—K—Co—Ni—Si—O catalyst after use, it disclosed that a solution containing MoO3, H3PO4, HNO3, and Bi(NO3)3 5H2O, H2O was impregnated with a catalyst for the purposes of the regeneration. Consequently such catalyst may be reused for the manufacture of acrylonitrile from propylene.
The U.K. Patent No. 1,518,215 in 1978 (Societa Italiana Resine S.p.A) disclosed the process, wherein, to a (NH4)6Mo7O24 solution, hydrochloric acid was added, and with further addition of Fe(NO3)39H2O solution, the mixture was dried, pulverized and calcined. Then, Bi(NO3)35H2O solution was sprayed to the residue, dried and calcined repeatedly to obtain the catalyst. It was reported that acrylonitrile with about 70% of selectivity was obtained at the temperature of 455° C.
Standard Oil Co. of U.S.A. reported the process in which Bi(NO3)3 5H2O solution was mixed with (NH4)6Mo7O24 solution in one reactor to obtain solution A with adjustment of pH. Then, solution B containing KNO2, Ni(NO3)3 6H2O, Co(NO3)2 6H2O, and Fe(NO3)3 9H2O in another reactor was prepared. Further, H3PO4 and silica sol were mixed in another reactor, after which solution A was added to the mixture, followed by the addition of solution B. Then, the mixed solution was dried, calcined and pulverized. The typical catalyst included [50%][Bi2Mo3O12]½[K01Ni25Co45FefP0.5MomO2H+50% SiO2] based on the method herein. The portion of such catalyst was assumed that it was composed of two phases, namely a key catalytic phase and a host-catalyst phase. But this terminology is used for descriptive purposes only because they were actually not composed of a simple mixture. Such catalyst was characterized in that the yield of both acrylonitrile and HCN were increased while the consumption of ammonia was reduced (U.S. Pat. No. 1,212,766).
In addition, Standard Oil Co. of U.S.A. reported the process using a catalyst comprising a composite oxide consisting of Mo, Fe and Bi, and atoms in the groups of 1A, 2A, 3A, 4A and 5A in the periodic table, which was prepared by impregnating potassium with a solution of potassium acetate. The yield of 80% to acrylonitrile was obtained at 430° C. in the presence of such catalyst, and in particular, the impregnating catalyst was superior to that of the conventional non-impregnating catalysts in terms of yields (Japanese Unexamined Publications Sho 83-143,842 and U.S. Pat. No. 4,144,134).
Nitto Chemical Industry Co. of Japan disclosed a process of manufacturing a catalyst derived from Mo—Bi—Fe—Ni—Si—O in such a manner that a slurry or dispersed solution consisting of Mo and Fe was prepared by the adjustment of pH. While heating the solution, other components were added therein, followed by spray-drying or thermal treatment to obtain a fluidized bed catalyst. The final product had the following characteristics in the presence of such catalyst at 450° C.: conversion of propylene was 98.8%, and selectivity was 83.2% to acrylonitrile (Japanese Patent No. 89,265,067).
The Standard Oil Co. of U.S.A. disclosed a catalyst for ammoxidation containing the following active ingredients an oxide of Mo, Bi, Fe, Co, Ni and Cr, and P, Sb, alkali, metals, alkaline earth metals, or rare earth metals (U.S. Pat. No. 5,134,105).
Technische Hochschule Carl Schorlemmer Leuna-Merseburgh Co. of Germany reported a method of manufacturing a catalyst in such a manner that Bi(NO3)35H2O was impregnated with an oxide consisting of Bi, Mo, Cr, Fe, Co, Na, and Si, thereby enhancing the selectivity thereof (German Patent No. 4,124,666 and No. 4,200,006).
In addition to the above cited patents, many researchers have conducted and intensive studies have been made on such catalysts.
Burkhardt, I. et al. of Germany reported that in line with the method of manufacturing a Fe2O3MoO3/SiO2 catalyst, the acidity was changed with the addition of Fe in the MoO3/SiO2 catalyst depending on the nature of oxidation and reduction. The research on the activity of ammonia on catalyst was carried out by infrared spectrophotometer (React. Kinet. Catal. Lett. 1987, 34(2), 309-15).
Kripylo, Peter, et al. of Germany carried out a research on the topic of the relationship between the structure and activity with respect to the Bi—Mo multicomponent oxides. It was reported that the active phase in the Bi—Mo catalyst had a structure comprising Fe, Co and Cr ions between the layer of MoO3. The ions were of significance to the formation of the active phase. Further, if the contents of Bi increased, the selectivity of acrylonitrile was further enhanced in proportion thereto (Chem. Tech. 1991, 43(3), 116-20).
In addition, Caldararu, H et al. studied the site of Fe34 ion relating to Bi2FeMo2O12 and Bi2Fe2Mo2O12 having a schcelite structure so as to observe the changes in the catalytic activity depending on the structure thereof. For example, the Fe34 ion in Bi2FeMo2O12 having tetragonal or monoclinic form was located on the tetrahedral site, and this location was not affected by reduction (Z. Phys. Chem. 1992, 177(1), 75-92).
Mehner, H. et al. reported that according to the surface analysis and transmission electron microscopy, the active phase relating to the reaction in a catalyst derived from a multicomposite molybdenum oxides was not present on the surface. Further, it was reported that all of components were participated in the reaction therein (Mater. Sci. Eng., B 1994, 25(1), 1-4).
As explained above, much research for the better catalytic activity has been made in various aspects of the catalyst.